A LALR(1) Parser Generator for JavaScript written in JavaScript
JS/CC is a parser generator for JavaScript/ECMAScript, which is entirely written in ECMAScript itself. It produces LALR(1) parsers with integrated lexical analyzers. JS/CC can run as a website or be invoked from a console, and runs on several platforms.
jsBison is a parser generator which can read bison style grammar definitions and generates according parsers written solely in javascript. Therefore, using jsBison it is easily possible to perform "real" parsing on websites on the client side.